In the gloaming

 

 From Cotati, 10 September 2019

Lobos Rock

I've been reviewing photos from our short visit to Monterey County in late August.  Here's a view of one of the Lobos Rocks near Garrapata State Park.  I hadn't taken a photo of this offshore rock with a larger lens before.  While scanning this image, I realized there were quite a few sea lions ("lobos marinos") on the rock.  Can you see some of them?  [You can click on the photo for a larger version.]

 

Eventually I noticed there were a few sea lions near the peak of the rock. Here's a zoomed in view.  Check the uppermost right hand corner:

 

So, which route do you think the sea lions took to reach the top?

 

Cobalt blue

I haven't posted much about sponges.  That's primarily because they can be a little more challenging to identify.  The species featured tonight, however, is quite distinctive.

Sponges are animals and have skeletons comprised of elements called spicules.  Some species have spicules made of calcium carbonate, but most have spicules made of silicon dioxide.  The spicules are wrapped in elastic fibers that together make up the wall of the sponge.

As with the ossicles of sea cucumbers (featured previously), sponge spicules come in a diversity of sizes and shapes.  The characteristics of the spicules can often be used to identify the species.

This particular sponge can basically be identified by its color alone, but we also checked the spicules to confirm the identification.

Many encrusting animals in the low intertidal zone are variations of yellow, red, orange, pink, and sometimes purple, brown, gray, or white.  This one stands out because it's brilliant cobalt blue:

 

Meet the Cobalt Sponge (Acanthancora cyanocrypta)!

We noticed this sponge under a rock overhang in the low intertidal zone in Monterey County.  It's primarily a southern species (distributed from Monterey south), but has also been reported in British Columbia.  We haven't seen it in northern California.

Note the species name — "cyanocrypta."  This sponge has symbiotic cyanobacteria (which apparently contributes to the amazing blue color).  Crypta means hidden, so I'm guessing cyanocrypta refers to the cyanobacteria living within the sponge.

Now for the spicules.  Here's an example of the types of spicules in Acanthancora cyanocrypta:

 

Figures modified from The Sponges of California: A guide and key to the marine sponges of California (Lee, Elvin, and Reiswig, 2007).

 

Note the different shapes — the long, simple tornotes; the club-like and spiky acanthostyles; and the barbell-like amphiasters.

Eric took some nice photos of the spicules so you can compare.  Remember, the spicules are microscopic.  In the images below, they are magnified 400x.  See if you can find all three types of spicules in the next three pictures:

 

 

 

There are over 250 species of marine sponges in California, so perhaps we'll be able to feature a few other species in future posts.

Feather duster

 

Yes, you guessed it, another outstanding tubeworm.  This one is a Giant Feather Duster Worm, Eudistylia polymorpha.  It was also photographed in Monterey County on 31 August 2019.  You can find this species locally, although the individuals we see in Bodega Bay are more often a solid, deep red/maroon color.

Spiralling in

 

A beautiful tubeworm, Spirobranchus spinosus, photographed in the low intertidal zone in Monterey County on 31 August 2019.

 

Dream waves

I mentioned that the light and sea conditions were interesting on the boat trip to Bodega Canyon and Cordell Bank on 25 August 2019. Here are a few more examples.  [You can click on the images for larger versions.]

Dream wave:

 

Just a hint:

 

Glide (Black-footed Albatross):

 

Gray on gray (Red Phalarope):

 

Power surge

 

I didn't get a chance to finish "pelagic week," so I'll be sharing a few more photos from the boat trip to Bodega Canyon and Cordell Bank on 25 August 2019.

Tonight's post features Pacific White-sided Dolphins (Lagenorhynchus obliquens).